Mobile vacuum apparatus for collection of liquid or semi-liquid materials

ABSTRACT

The apparatus comprises a vacuum tank with a front-mounted collection means thereunder The collection means is a V-shaped scraper with a height adjustable suction inlet at the apex thereof. The collection means has a pair of laterally adjustable pivoting wings for varying its width to correspond to that of an alley or gutter. The suction inlet may be equipped with a snorkel to introduce a small quantity of air as an aid in entraining thick-consistency materials. A blower vac is used to both draw air into and blow air through the vacuum tank. A valve means comprising a pair of oppositely oriented check valves is used to alternate flow paths between a lowered rearward exhaust during collection and an elevated intake during tank discharge.

This application is a continuation of U.S. patent application Ser. No.11/113,303, filed Apr. 25, 2005, now U.S. Pat. No. 7,797,789, issuedSep. 21, 2010, the contents of which is incorporated herein byreference.

FIELD OF THE INVENTION

The invention relates to the mobile pneumatic collection of liquid orsemi-liquid materials such as animal manure. More specifically, theinvention relates to a mobile vacuum apparatus having a collection meansmounted thereunder that directs the liquid or semi-liquid materials intoa suction inlet when the apparatus is driven through the materials.

BACKGROUND OF THE INVENTION

Animal husbandry facilities, such as dairy or hog barns, include alleysor gutters for manure collection. Vehicles such as tractors orskid-steer loaders are equipped with scraper blades or front-end bucketsystems to transfer manure accumulated in the alley or gutter to one endof the barn for removal and disposal. The manure is typically liquid orsemi-liquid and is often difficult to transfer in this manner, as itescapes around the sides of the scraper blade or bucket. In addition,with the very large facilities that are becoming quite common in moderndairy farming, sometimes with an overall length in excess of 1000 feet,the quantity of accumulated material is too great to transfer to one endof the facility. As a result, there is a need for improvements in thecollection and removal of manure from animal husbandry facilities.

Pneumatic collection of agricultural debris is used in a variety ofoperations both on and off the farm. For example, in the clean-up ofspills of dry solid materials, such as grain or agricultural chemicalslike fertilizer, vacuums are employed to pneumatically transfer thespilled materials to a storage container. An example of such a vacuumapparatus is provided in U.S. Pat. No. 4,218,226. These types ofmachines are not particularly well-suited to the collection of liquid orsemi-liquid materials such as animal waste. Moreover, they lack any typeof collection means for mounting beneath the apparatus to direct thecollected material to the suction inlet when the apparatus is drivenover the material, making them difficult to use in large scale mobilecleanup operations. Vacuum systems have been used for mobile cleanup ofrelatively dry manure, such as chicken and horse manure. U.S. Pat. No.5,010,620 discloses a stall and pasture vacuum machine that includes afront mounted sled comprising a rotary brush. A mist of water may beprovided to soften the manure and make it more amenable to pneumaticconveying. The collected manure is stored in a dump box with a hingedrear door. This machine is not suitable for the cleanup of liquid orsemi-liquid materials.

Vacuum systems have been used in the clean-up of liquid and semi-liquidanimal waste. U.S. Pat. No. 3,585,670 discloses an apparatus comprisinga vacuum tank and a rear-mounted V-shaped scraper blade. However, inmounting the scraper blade at the rear of the apparatus, the manure iscompacted prior to being collected, making it difficult to separate fromthe barn floor and difficult to convey pneumatically.

Another vacuum apparatus for the collection of liquid or semi-liquidmanure is manufactured by Loewen Welding & Manufacturing (Matsqui, BC,Canada) under the trade-name Honey-Vac®. In this apparatus, thecollected manure enters the back of the vacuum tank from the topthereof. Since the collected manure is also discharged from the back,there is no complete flushing from front to rear during discharge. Thisleads to an accumulation of manure in the front of the tank thatdiminishes tank capacity after repeated use. The accumulated manure mustbe periodically cleaned out through manual access hatches, which is adangerous and unpleasant task. Also, the apparatus makes use of separateblower and vacuum pumps, which creates mechanical complexity andincreases down time.

As a result, there remains a need for an improved material collectionapparatus, particularly for liquid and semi-liquid materials such asanimal manure.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided amobile vacuum apparatus for collection of liquid or semi-liquidmaterials, the apparatus comprising: a frame having a front and rear; aset of wheels mounted under the frame; a vacuum tank for receivingcollected liquid or semi-liquid materials, the vacuum tank having avacuum inlet at a front thereof and a vacuum outlet at a top thereof; acollection means comprising a scraping element mounted under the frontof the frame, the collection means in fluid communication with thevacuum inlet; a discharge outlet at a rear of the tank; and, a blowervac capable of drawing air from the vacuum tank through the vacuumoutlet to thereby create a vacuum in the tank.

According to another aspect of the invention, there is provided a mobilevacuum apparatus for collection of liquid or semi-liquid materials, theapparatus comprising: a frame having a front and rear; a set of wheelsmounted under the frame; a vacuum tank for receiving collected liquid orsemi-liquid materials, the vacuum tank having a vacuum inlet at a frontthereof and a vacuum outlet at a top thereof; a collection means influid communication with the vacuum inlet; a discharge outlet rearwardof the collection means; a blower vac selectively capable of eitherdrawing air from the vacuum tank through the vacuum outlet to therebycreate a vacuum in the tank or blowing air into the vacuum tank tothereby expel the collected liquid or semi-liquid materials therefromunder pressure through the discharge outlet; and, a valve means fordirecting air to a blower vac exhaust when drawing air from the vacuumtank and for supplying air from an elevated blower vac intake whenblowing air into the vacuum tank.

The apparatus is mobile and may be either pulled by a towing vehicle orself-propelled. The towing vehicle may be a farm tractor and theapparatus is particularly suitable for agricultural use. The apparatusis designed to be driven over the material to be collected with thecollection means in front to reduce compaction of the material beingcollected. The material being collected may be any type of liquid orsemi-liquid material suitable for pneumatic conveying. The material maycomprise liquid waste. The material may comprise animal manure, such asmanure from cows or pigs, and the animal manure may be in a semi-liquidstate. The apparatus may be adapted for use in an animal husbandryfacility, such as a dairy barn or milking shed, particularly such afacility that includes alleys or gutters for collection of manure.

It is desirable that the collected material is prevented from enteringthe blower vac, as obstruction of its internal moving parts can causesignificant damage to the blower vac. The vacuum tank includes a vacuumoutlet that may comprise two or more vacuum outlets spaced apart alongthe top of the tank. By using two or more vacuum outlets, the velocitythrough each outlet is decreased, thereby reducing the likelihood thatthe collected material can become entrained in the air flowing throughthe outlets. The outlets may be of the same size or different sizes inorder to preferentially direct the collected material to different partsof the tank. Each outlet may include a primary trap to further reducethe likelihood of material escaping through the vacuum outlet,particularly when the tank is full. Any suitable primary trap design maybe used and the primary trap is preferably readily cleaned by reducingthe air flow through the vacuum outlet.

Air flowing from the vacuum outlet may be directed to a secondary trapfor yet further reducing the likelihood that entrained debris will enterthe blower vac. The secondary trap may be of any suitable design and maycomprise a chamber containing a series of baffle plates that arearranged to create a serpentine path. Alternatively, the chamber maycontain a plurality of perforated impingement plates stacked with theperforations in an offset relationship. The secondary trap may besimilar to a knock-out pot in that it may be designed for the removal ofliquid from the air flow, particularly liquid droplets. The secondarytrap may be cleaned by reversing the direction of air flow through thetrap and may be additionally or alternatively cleaned using asupplemental stream of air or water to flush out the contents of thetrap. The secondary trap may include a drain and the drain may bedirected back into the vacuum tank. The outlet of the secondary trap ispreferably free of collected material or droplets and is provided to theblower vac.

The blower vac may be powered by a motor of the towing vehicle or by amotor mounted on the apparatus itself. A separate motor may be used toindependently power the blower vac. The towing vehicle may be connectedto the blower vac using a power take-off (PTO) mechanism. The blower vacmay comprise a single unit or two separate but connected units. Theblower vac may comprise two chambers connected to a single power source.The blower vac may comprise an internal valve that permits the flow paththrough the blower vac to be altered in order to switch the intake portof the blower vac to the exhaust port and vice versa. The blower vac maybe reversible in order to alternate intake and exhaust ports. The blowervac may comprise a positive displacement pump, such as a rotary vanepump. The blower vac may be in fluid communication with a valve means.

The valve means may be used as part of any liquid or semi-liquidmaterial collection system that both draws and expels materialpneumatically. The valve means may be automatically adjustable ormanually adjustable. The valve means may comprise a three-way valvemechanism that permits selection of a single flow path from twodifferent flow paths, for example and L-ported ball valve that may bealternated between two flow paths. The valve means may comprise a pairof check valves, one check valve in each of the intake and exhaust flowpaths. The check valves may be oppositely oriented to permit air to flowinto the valve means through only one flow path (the intake flow path)and out of the valve means by only the other flow path (the exhaust flowpath). In this manner, the valve means is automatically adjustable inresponse to a change in the direction of flow through the blower vac.The valve means may include a valve chamber and the check valves neednot necessarily both be located in the valve chamber. The valve means isparticularly advantageous in allowing an air intake and exhaust of thesystem to be separated, thereby permitting the intake to be elevatedwith respect to the material being collected and the exhaust to belocated distantly from the operator. The elevated exhaust reduces thelikelihood of debris entering the blower vac when blowing air into thetank and the distant exhaust improves operator health and safety.

The collection means may be any suitable mechanism for directing thematerial toward the pneumatic collection inlet and may include, forexample a brush, rotating brush, scraper, squeegee, air blast, waterjet, or a combination thereof. The scraper may comprise a scrapingelement made from a rigid yet flexible material, such as a highdurometer or reinforced rubber. The collection means may be heightadjustable and may be either self-leveling or manually level adjustedwith respect to the material collection surface. The suction inlet ofthe pneumatic collection system may be through a distribution means topermit collection across the width of the collection means or collectionmay occur at a discrete point or points. The collection means may have ashape adapted for funneling the material toward the suction inlet, forexample a V-shape when seen in plan view.

The suction inlet may be height adjustable independently of any heightadjustment of the collection means in response to the quantity ofmaterial being collected; this permits a scraping element of thecollection means to remain in contact with the floor surface whileallowing the suction inlet to be adjusted relative in height thereto inresponse to a large quantity of material being collected. Any suitablemechanism may be employed to adjust the height of the suction inlet. Thesuction inlet is preferably connected to the vacuum inlet by a flexibleconnection in order to facilitate the height adjustment. By setting thesuction inlet closer to the floor surface that the material is beingcollected from more material may be collected, thereby leaving lessmaterial in the collection means at the end of a pass through an alley.However, if set close to the floor, the suction inlet will have morematerial to pick-up and driving speed may have to be reduced. There istherefore an optimal trade-off between speed and completeness ofcollection. A snorkel may be provided alongside the suction inlet forintroducing a small quantity of air into the material as it is beingcollected. This small quantity of air is entrained with the material andmakes it easier to lift from the floor and easier to pneumaticallyconvey, particularly for materials with a thick consistency. The snorkelmay include a small valve to set the quantity of air provided to thesuction inlet according to the consistency of the material beingcollected.

The collection means may include a variable width mechanism. Thevariable width mechanism is particularly useful in the collection ofmanure from alleys or gutters, as it allows the collection means to fitthe width of the alley or gutter and reduces the likelihood of manureescaping around the sides of the collection means. The collection meansmay include wings that are pivotally attached to each side of thecollection means and able to pivot about a vertical pivot axis. Thewings may be biased outwardly towards or against the sidewalls of thealley or gutter and may resiliently adapt to changes in the width of thegutter by pivoting about the vertical pivot axis. The wings may moveabout the vertical pivot axis in response to a change in the distancebetween the side-wall of the alley and the collection means. The wingsmay be biased by a spring means or a suitable fluid cylinderarrangement, such as a pneumatic or hydraulic fluid displacementcylinder, a captive gas shock absorber, or a combination thereof. Thewings may automatically adjust to the width of the alley or gutter ormay be manually adjusted by an operator of the apparatus. The adjustmentmay be conducted using controls within the towing vehicle. The wings mayinclude skid plates or wear strips to reduce the likelihood of damagingthe wings due to operator driving error.

The discharge outlet is provided at the rear of the vacuum tank. Thedischarge outlet may be connected to any manure distribution systemsuitable for liquid or semi-liquid manure, such as a spreader plate orsub-surface injection system. Alternatively, the discharge outlet may beconnected via a fluid conduit for transferring the manure to a separatespreading apparatus or a holding vessel. The vacuum inlet is provided atthe front of the tank, preferably in a lower half thereof below thehorizontal midline of the tank. Filling the tank from the front anddischarging the tank through the rear causes a flushing of the collectedmaterials through the tank. This causes substantially all of thematerial in the tank to be discharged and mitigates material build-up inthe front of the tank. During collection, a remotely operable valve onthe discharge outlet is closed to prevent inadvertent leakage fromoccurring. During tank discharge, a remotely operable valve on thevacuum inlet is closed to prevent material from being discharged throughthe collection means.

Further features of the invention will be described or will becomeapparent in the course of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more clearly understood, embodimentsthereof will now be described in detail by way of example, withreference to the accompanying drawings, in which:

FIG. 1 a is a side view of the apparatus according to the presentinvention showing a flow path through the apparatus when material isbeing collected;

FIG. 1 b is a side view of the apparatus according to the presentinvention showing a flow path through the apparatus when material isbeing discharged;

FIG. 2 is a side view of the collection means of the present invention;

FIG. 3 is a top view of the collection means of the present invention;

FIG. 4 is a side view of the height adjustable suction inlet of thepresent invention;

FIG. 5 a is a schematic side view of the valve means of the presentinvention while air is being drawn from the vacuum tank; and,

FIG. 5 b is a schematic side view of the valve means of the presentinvention while air is being blown into the vacuum tank.

DESCRIPTION OF PREFERRED EMBODIMENTS

In describing the figures, like features are referred to by likereference numerals. Although not all features indicated on a particulardrawing are necessarily described with reference to that drawing, all ofthe features are described with reference to at least one of thedrawings.

Referring to FIGS. 1 a and 1 b, the mobile vacuum apparatus comprises avacuum tank 1 mounted on a frame 2 having a front and rear with a hitchmeans 3 for connection to a towing vehicle (not shown) at the front ofthe frame. A collection means 4 is mounted to the underside of the frame2 at the front thereof, forward of a discharge outlet 5 of the vacuumtank 1. A spreader means 6 is attached to a flange on the dischargeoutlet 5. A set of tandem wheels 8 is mounted to the underside of theframe 2 using a walking-axle arrangement as is conventionally known.

A blower vac 7 is provided at the front of the frame 2. The blower vac 7is a positive displacement rotary vane pump (in a preferred embodiment,a Wallenstein type pump) that can operate as either a blower or vacuumpump. The blower vac 7 is a single integrated unit capable ofselectively drawing air from the vacuum tank or blowing air into thevacuum tank. An integral valve (not shown) is provided as part of theblower vac 7 to switch between drawing air from and blowing air into thevacuum tank 1. The pump derives power from the towing vehicle via a PTOshaft 15.

FIG. 1 a schematically shows a flow path through the apparatus whenmaterial is being collected. The collection means 4 is lowered withrespect to ground level and parallel thereto with a scraper element 14in contact with the floor surface. Material is admitted into a suctioninlet (not shown in FIGS. 1 a and 1 b) of the collection means 4 anddrawn through suction conduit 37 into vacuum inlet 16 of vacuum tank 1.The vacuum inlet 16 is located on the front of the vacuum tank 1 in thelower half thereof below the horizontal midline of the tank. This causesthe collected material to fill the tank from front to rear, improvingweight distribution and facilitating substantially complete discharge.The air is then drawn out of the vacuum tank 1 through vacuum outlet 17,which comprises front vacuum outlet 17 a and rear vacuum outlet 17 b.The use of two vacuum outlets 17 a and 17 b reduces the exit airvelocity by half as compared with a single outlet, significantlyreducing the likelihood of debris becoming entrained and exiting throughthe vacuum outlet 17. Each vacuum outlet 17 a and 17 b is equipped witha primary trap 23 comprising a stainless steel ball float 18 captivatedwithin a rigid mesh cage 19. The rigid mesh cage 19 helps preventmaterial from exiting the tank 1 through the vacuum outlet 17. As thelevel of material in the vacuum tank 1 rises to the top of the tank, thefloat 18 rises and blocks the outlet 17 to prevent material from beingdrawn out of the tank. The primary trap 23 therefore serves as a firstline of defense in keeping the collected material within the tank 1.

Air drawn through the vacuum outlet 17 is next directed into secondarytrap 21 at the bottom thereof. The secondary trap 21 includes aplurality of stacked baffles 22 arranged to create a serpentine flowpath through the trap 21. This causes disengagement of any materialsentrained in the air flow, particularly liquid materials which may havepassed the mesh cage 18 of the primary trap 23. The secondary trap 21includes a drain (not shown) for re-introducing any collected materialback into the vacuum tank 1. The secondary trap 21 may be cleaned usingsupplementary flows of water or air provided through ports (not shown)at the top thereof. The exit of the secondary trap 21 is protected by astainless steel ball float 18 captivated within a rigid mesh cage 19 inan arrangement similar to that of the primary trap 23.

Air exiting the secondary trap 21 is provided to the blower vac 7through first blower vac conduit 24 and exits therefrom through secondblower vac conduit 26. The air is provided to a valve means comprising avalve chamber 50 and pressurizes the valve chamber, causing the secondclosure means 60 to open and allowing the air to exit through theanterior end of blower vac exhaust 52.

In FIG. 1 b, the apparatus is illustrated in a tank discharge condition.The blower vac 7 creates a negative pressure or vacuum in the valvechamber 50. This causes the first closure means 54 to open, admittingair into the valve chamber 50 through blower vac intake 51. The air thenflows through the second blower vac conduit 26 into the blower vac 7,which acts to blow the air out through first blower vac conduit 25. Theair flows downwardly through the secondary trap 21, back flushing anyaccumulated debris out through the drain (not shown) and into tank 1.The air then passes out of the bottom of the secondary trap 21 and intothe vacuum outlet 17 at the top of the vacuum tank 1. The primary trap23 is back flushed to dislodge any debris accumulated against the meshcage 19. A positive pressure is created in the vacuum tank 1, whichforces the collected material outwardly through rear discharge outlet 5.A remotely operable discharge valve (not shown) is opened duringdischarge to allow material to exit through the spreader means 6 and isclosed during collection of material. Conversely, a remotely operablesuction valve (not shown) is closed during tank discharge to preventmaterial from exiting through the collection means 4 and is openedduring collection of material.

The introduction of air through the first vacuum outlet 17 a causesmaterial accumulated at the front of the tank to be pushed downwardlyand out through the discharge outlet 5. In this manner, a completeflushing of the vacuum tank 1 occurs to expel substantially all of thematerial in the tank (as compared with prior art systems) reducing theneed for manual cleanout of the front of the vacuum tank.

Referring to FIGS. 2 and 3, the collection means 4 is pivotally mountedto the underside of the frame 2 by way of pivot arm 10. Pivot arm 10 ispivotally attached at one end to a central portion 29 of the collectionmeans 4 at first pivot pin 27 and at the other end to the frame 2 atsecond pivot pin 28, which is located between the tandem wheels 8. Ahydraulic lift cylinder 9 is provided between the central portion 29 andthe frame 2 and may be extended or retracted to lower or raise,respectively, the collection means 4 by pivoting of the pivot arm 10about the second pivot pin 28. The collection means 4 is typicallyraised when turning the apparatus to prevent damage to the collectionmeans due to skid-induced lateral forces.

An adjustable length link 11 is pivotally attached at one end to anupwardly extending stub 12 fixedly mounted on the pivot arm 10. Theother end of the link 11 is pivotally attached to the central portion 29at link pivot 13, which is located above the first pivot pin 27. Byadjusting the length of the link 11, a fine tilting adjustment of thecentral portion 29 may be attained so as to ensure that the scraperelement 14 attached to the underside of the collection means 4 remainsin contact with the floor or other surface from which the materials arebeing collected. The scraper element 14 comprises a high durometerrubber scraping edge with a steel reinforcement. This permits thescraping element 14 to conform somewhat to irregularities in the scrapedsurface while providing sufficient rigidity to remove adherentmaterials. The rubber scraping edge also provides a squeegee effectsimilar to an automotive windshield wiper that permits liquid orsemi-liquid materials to be scraped.

The collection means 4 further comprises a pair of laterally adjustablewings 30 that are attached to the central portion 29 on opposite sidesthereof. Each wing 30 is pivotally attached to the central portion 29using a piano hinge 31 that allows the wing to pivot about a verticalpivot axis passing through the center of the hinge. A hydraulic wingcylinder 32 is pivotally attached to each wing 30 and to central portion29 so that extension of the wing cylinders causes the wings to open,thereby increasing the width of the collection means 4. The wings 30 areclosed by retracting the wing cylinders 32. The normal range of movementof the wings 30 is from a closed position parallel to the longitudinalaxis of the apparatus (defined by its direction of travel) to an openposition which is at an angle less than perpendicular to thelongitudinal axis and preferably tangential to the central portion 29 atthe hinges 31. FIG. 3 shows the closed position (marked A) and alsoshows the open position (marked B) in phantom lines. In the openposition, the wings 30 extend past the wheels 8. The wings 30 arenormally closed when transporting the apparatus to reduce the risk ofdamaging the wings.

The wings 30 may be controlled using a single circuit so that they bothopen and close at the same time or using separate circuits so that oneor the other of the wings may be opened or closed. In addition, thewings 30 need not be completely opened, but can be set to any desiredangle of opening. This is particularly advantageous when scraping alarge area without side-walls. When scraping an alley or gutter withside-walls, such as in an animal husbandry facility, the wings 30 arepreferably opened until a skid protector 33 attached to the distal endof each wing comes into contact with the side-wall. The skid protector33 may be made from metal or a durable plastic, preferably a plasticwith dry lubricant qualities such as Delrin®. A pressure relief valve(not shown) is provided in each hydraulic circuit of the wing cylinders32 in order to permit the wings 30 to close by rotating about thevertical pivot axis in response to a decrease in distance between thecollection means 4 and the side-wall. The valves may be adjusted tomaintain a modest cylinder extension pressure so that the wings 30return to the desired pre-set open position when the distance betweenthe collection means 4 and the side-wall increases. The net effect isthat closing of one wing 30 due to distance changes while driving ismatched by a corresponding opening of the opposite wing.

A height adjustable suction inlet 20 is provided at about the center ofthe central portion 29. Referring to FIG. 4, the suction inlet 20 has a45.degree. degree bend so that a lower portion 34 forms a downwardlyoriented nozzle opening 35 that is roughly parallel with the floor(subject to fine level adjustment using adjustable length link 11). Theupper portion 36 of the suction inlet 20 is attached one end of flexiblesuction conduit 37. The other end of suction conduit 37 is attached tothe vacuum inlet 16 of vacuum tank 1. The flexible suction conduit 37permits the height of the suction inlet 20 to be adjusted withoutconstraint by the conduit. An upright post 38 is fixedly attached to thesuction inlet 20. The central portion 29 has an inverted L-shapedcross-section with a top portion 39 to which a collar 40 is mounted. Thecollar 40 is forwardly offset from the central portion 29 and has a borethat is complementary in size to the upright post 38. The bore permitssliding passage of the upright post 38 through the collar 40. Auser-adjustable set screw 41 is provided in the collar 40 for threadingengagement with the upright post 38. By loosening the set screw 41, theupright post 38 is permitted to slide through the bore of the collar 40,allowing the height of the suction inlet 20 to be raised or loweredrelative to ground level. Tightening the set screw 41 allows the desiredheight of the suction inlet 20 to be fixed. During forward travel of theapparatus in the direction indicated by arrow C, the liquid orsemi-liquid material being collected accumulates within the invertedL-shaped cross section of the central portion 29 and is constrained fromoverflowing by the top portion 39 thereof. The height of the suctioninlet 20 is typically adjusted higher for thick semi-liquid materialsand lower for liquid materials.

A snorkel 43 is provided alongside the suction inlet 20. The snorkel 43permits a small quantity of air to be introduced into the opening 35 forentrainment with the materials being collected by the suction inlet 20.It has been found that the introduction of air by the snorkel 43 is ofparticular use in the collection of thick semi-solid materials, as thetwo-phase flow produced tends to aid in pneumatically conveying thematerials into the vacuum tank 1. A snorkel valve 44 may be adjusted todeliver the desired amount of air to the suction inlet 20 according tothe consistency of the materials being collected.

Referring to FIGS. 5 a and 5 b, a valve means is schematically shown aspart of the blower vac intake/exhaust system. A valve chamber 50 isprovided with an elevated blower vac intake 51 extending upwardlytherefrom and a blower vac exhaust 52 extending downwardly therefrom.The second blower vac conduit 26 extends from the side of the valvechamber 50 and permits flow in either direction between the blower vac 7and the valve chamber. The second blower vac conduit 26 is preferablyprovided tangentially to the valve chamber 50 and laterally offset fromthe vertical centerline thereof to create a swirling flow pattern andcyclonic action within the valve chamber. The valve chamber 50 can beshaped and/or include supplementary flow elements to enhance this flowpattern. The cyclonic action is used as an aid in removing dust ordebris when the blower vac intake 51 is being used to supply air forblowing into the vacuum tank 1.

FIG. 5 a shows the valve means in operation when drawing air from thevacuum tank 1. A first closure means 54 is pivotally attached to thelower end of the blower vac intake 51 within the valve chamber 50 byclosure hinge 55. The first closure means 54 has a counterweight 56 onan opposite side of the closure hinge 55 from the blower vac intake 51.The counterweight 56 biases the first closure means 54 into a closedposition to seal the end of the blower vac intake 51. The valve chamber50 is pressurized when air is drawn from the vacuum tank 1 and the airpressure helps maintain the first closure means 54 in a closed position.The pressurized air escapes through blower vac exhaust 52. The blowervac exhaust 52 is downwardly oriented from the valve chamber 50 and isrouted along the underside of the frame 2. An opening at the anteriorend of the blower vac exhaust 52 directs the foul-smelling air drawnfrom the vacuum tank 1 downwardly and away from the operator of theapparatus, who is located in the towing vehicle attached to the fronthitch means 3. This improves the overall health and safety of theoperator. A second closure means 60 is pivotally attached to theanterior end of the blower vac exhaust 52. A closure weight 61 isprovided to bias the second closure means 60 into a closed position overan opening in the anterior end of the blower vac exhaust 52. However,the flow of pressurized air provided from the valve chamber 50 issufficient to overcome this bias and causes the second closure means 60to open, thereby allowing air to escape through the opening.

Referring to FIG. 5 b, the valve means is shown in operation during tankdischarge when the blower vac 7 is used to blow air into the vacuum tank1. The flow path through the second blower vac conduit 26 is reversed ascompared with FIG. 5 a and the valve chamber 50 is under vacuum. Thevacuum overcomes the bias provided by the counterweight 56 and causesthe first closure means 54 to open, admitting air into the valve chamber50 through the blower vac intake 51. A filter 59 is provided atop theblower vac intake 51 to remove debris from the intake air stream inorder to reduce the potential for damage to the blower vac 7. Thenegative pressure within the valve chamber 50 enhances the bias on thesecond closure means 60 provided by the closure weight 61 and acts toseal the blower vac exhaust 52.

By referring to FIGS. 5 a and 5 b, it can be seen that the first andsecond closure means 54 and 60 of the valve means act as oppositelyoriented check valves that permit flow in only one direction througheach of the blower vac intake 51 and blower vac exhaust 52. The valvemeans permits flow through one flow path or the other, depending on thedirection of flow through the second blower vac conduit 26. The firstand second closure means 54 and 60 automatically close or open accordingto whether air is being drawn from the vacuum tank 1 or blown into thevacuum tank 1.

Other advantages which are inherent to the structure are obvious to oneskilled in the art. The embodiments are described herein illustrativelyand are not meant to limit the scope of the invention as claimed.Variations of the foregoing embodiments will be evident to a person ofordinary skill and are intended by the inventor to be encompassed by thefollowing claims.

1. A mobile vacuum apparatus for collection of liquid or semi-liquidmaterials, the apparatus comprising: a) a frame having a front and rear;b) a set of wheels mounted under the frame; c) a vacuum tank forreceiving collected liquid or semi-liquid materials, the vacuum tankhaving (i) a vacuum inlet in a front wall thereof and (ii) two or morevacuum outlets spaced apart along a top thereof and in fluidcommunication with one another through a structure on an outside of thetank; d) collection structure comprising a scraping element mountedunder the front of the frame, the collection structure in fluidcommunication with the vacuum inlet; e) a discharge outlet at a rear ofthe tank; and, f) a blower vac selectively (i) drawing air from thevacuum tank through the two or more vacuum outlets to thereby create avacuum in the tank, or (ii) blowing air into the vacuum tank through thetwo or more vacuum outlets to thereby expel the collected liquid orsemi-liquid materials therefrom under pressure through the dischargeoutlet.
 2. A mobile vacuum apparatus according to claim 1, wherein thecollection structure includes a pair of wings pivotally attached onopposite sides of the collection structure and movable about a verticalpivot axis to vary a width of the collection means.
 3. The apparatusaccording to claim 2, wherein the wings are configured to (i) be biasedagainst a side-wall of an alley and (ii) move about the vertical pivotaxis in response to changes in distance between the side-wall and thecollection means.
 4. The apparatus according to claim 1, wherein thecollection structure includes a suction inlet in fluid communicationwith the vacuum inlet.
 5. The apparatus according to claim 4, whereinthe suction inlet includes a snorkel that permits air to be entrainedwith the collected material entering the suction inlet.
 6. The apparatusaccording to claim 1, wherein the vacuum inlet is at a front of the tankin a lower half thereof.
 7. The apparatus according to claim 1, whereinthe apparatus further comprises a valve configured to (i) direct air toa blower vac exhaust located beneath the frame when drawing air from thevacuum tank, and (ii) to supply air from a separate elevated blower vacintake located above the frame when blowing air into the vacuum tank. 8.A mobile vacuum apparatus for collection of liquid or semi-liquidmaterials, the apparatus comprising: a) a frame having a front and rear;b) a set of wheels mounted under the frame; c) a vacuum tank forreceiving collected liquid or semi-liquid materials, the vacuum tankhaving (i) a vacuum inlet at a front thereof and (ii) at least twovacuum outlets spaced apart on a top of said tank, the at least twovacuum outlets being in fluid communication with each other through astructure separate from the portion of the tank which holds the liquidor semi-liquid materials; d) a collection structure comprising ascraping element mounted under the front of the frame, the collectionstructure in fluid communication with the vacuum inlet; e) a dischargeoutlet rearward of the collection structure; f) a blower vac selectively(i) drawing air from the vacuum tank through the at least two vacuumoutlets to thereby create a vacuum in the tank or (ii) blowing air intothe vacuum tank to thereby expel the collected liquid or semi-liquidmaterials therefrom under pressure through the discharge outlet; and g)a valve configured to (i) direct air to a blower vac exhaust locatedbeneath the frame when drawing air from the vacuum tank, and (ii) tosupply air from a separate elevated blower vac intake located above theframe when blowing air into the vacuum tank.
 9. The apparatus accordingto claim 8, wherein the blower vac exhaust is located at the rear of theapparatus.
 10. The apparatus according to claim 8, wherein the valvecomprises (i) a blower vac exhaust check valve that is closed whenblowing air into the vacuum tank and (ii) a blower vac intake checkvalve that is closed when drawing air from the vacuum tank.
 11. Theapparatus according to claim 8, wherein the valve comprises a valvechamber that is pressurized when drawing air from the vacuum tank andevacuated when blowing air into the vacuum tank.
 12. The apparatusaccording to claim 11, wherein the valve chamber has a blower vac intakeat a top thereof with a first closure that opens when the valve chamberis evacuated to admit air into the valve chamber and closes when thevalve chamber is pressurized to prevent air from escaping through theblower vac intake.
 13. The apparatus according to claim 12, wherein thevalve chamber has a blower vac exhaust at a bottom thereof with a secondclosure that opens when the valve chamber is pressurized to allow air toescape from the valve chamber and closes when the valve chamber isevacuated to prevent air from entering the valve chamber through theblower vac exhaust.
 14. The apparatus according to claim 8, wherein theat least two vacuum outlets is disposed on a front half of the tank, andwherein at least one other of the at least two vacuum outlets isdisposed on a back half of the tank.
 15. The apparatus according toclaim 8, wherein the collection structure includes a pair of wingspivotally attached on opposite sides of the collection structure andmovable about a vertical pivot axis to vary a width of the collectionstructure, the wings configured to be biased against a side-wall of analley and moving about the vertical pivot axis in response to changes indistance between the side-wall and the collection structure.
 16. Theapparatus according to claim 8, wherein the collection structureincludes a suction inlet in fluid communication with the vacuum inlet,the suction inlet variable in height with respect to ground levelindependently of a height of the collection structure.
 17. The apparatusaccording to claim 1, wherein each of the vacuum outlets comprises aprimary trap comprising a ball float for reducing the likelihood ofcollected liquid or semi-liquid materials exiting the tank.
 18. Theapparatus according to claim 14, wherein the vacuum outlets are in fluidcommunication with one another both outside the tank and inside thetank.
 19. The apparatus according to claim 8, wherein each vacuum outletcomprises a primary trap comprising a ball float for reducing thelikelihood of collected liquid or semi-liquid materials exiting thetank.
 20. The apparatus according to claim 1, wherein the suction inletcomprises a lower portion with a downwardly oriented nozzle opening. 21.A mobile vacuum apparatus collecting semi-liquid animal waste materials,the apparatus comprising: a frame having a front and rear; a set ofwheels mounted under the frame; a vacuum tank for receiving collectedsemi-liquid animal waste materials, the vacuum tank having (i) a vacuuminlet in a front thereof and (ii) two or more vacuum outlets spacedapart along a top thereof and in fluid communication with one anotherthrough a structure separated from the animal-waste-material-containingportion of the tank; collection structure comprising a scraping elementmounted under the frame, the collection structure in fluid communicationwith the vacuum inlet, the collection structure including a suctioninlet in fluid communication with the vacuum inlet, wherein the suctioninlet includes a snorkel that permits air to be entrained with thecollected material entering the suction inlet; a discharge outlet at arear of the tank; and, a blower vac selectively (i) drawing air from thevacuum tank through the two or more vacuum outlets to thereby create avacuum in the tank, or (ii) blowing air into the vacuum tank through thetwo or more vacuum outlets to thereby expel the collected liquid orsemi-liquid materials therefrom under pressure through the dischargeoutlet.